This is shown by a new study published in the renowned research journal Nature. – I was surprised that there was so much ice that has not been included in the calculations before, says Elin Darelius, professor of physical oceanography at the University of Bergen. She has looked at the new study. It is well known that much of Greenland’s ice has melted as a result of global warming. But previous calculations have not considered changes in where the front of glaciers located in fjords is located. According to the study, Greenland has lost 5,000 square kilometers of ice in this way between 1985 and 2022. This corresponds to one thousand gigatonnes – or one thousand billion tonnes – more lost ice. Greenland may thus have lost 20 percent more ice than we thought. It has not been possible to detect that this area is changing, explains Darelius. But in the new study, the researchers believe they have cracked the code with new methods. Melting glacier in Scoresbysund. Photo: OLIVIER MORIN / AFP Answers found with artificial intelligence The researchers have now, among other things, used artificial intelligence to analyze satellite images. This is how they have mapped the endpoints of the glaciers in Greenland for each month over 37 years. They analyzed over 236,328 endpoints to reach their conclusion. With the exception of one glacier that experienced modest growth, the findings tell a clear story: – Almost every glacier in Greenland is retreating. And it’s like that wherever you look, says glacier scientist Chad Greene at NASA to the New York Times. He is the lead author of the study. – The withdrawal is happening everywhere and at the same time, he says. The findings are important, says Darelius. According to the study, the extra meltwater has led to a small degree of sea level rise, because the ice that melted was already partly under water. – But it affects how the ice behind moves, says Darelius. When the underwater ice disappears, it can help speed up melting on land, writes Bloomberg. And that contributes to rising sea levels. Ice drifts away from a glacier in Scoresbysund. Photo: OLIVIER MORIN / AFP Does not affect sea level Another thing scientists are concerned about is the effect the additional melting may have on the AMOC, or Atlantic Meridian Overturning Circulation. This is known as the engine of part of the important Gulf Stream. It has a direct effect on our lives and affects our weather and climate. This picture shows how the AMOC system works. The Gulf Stream belongs to this system. Photo: Stefan Rahmstorf (Nature 1997), Creative Commons BY-SA 4.0. When ice melts in Greenland, large quantities of fresh water are dumped into the sea. It can weaken the AMOC. This is a question many oceanographers working in the north are concerned with, says Darelius. – Additional freshwater supply from Greenland does not strengthen the AMOC, so to speak, she says. The state of the AMOC, whether and when it might collapse, has been the subject of much debate among scientists. Now Chad Greene hopes their new findings can be used to find more answers. – We found a thousand extra gigatonnes of lost ice. Now we’re saying to ocean modellers: ‘put this in your models and see if it affects things,'” Greene told The Guardian.
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The Greenland ice sheet may have melted 20 percent more than we thought – news – Klima
